Mastic Joint or Deck-O-Seal? What is is???
An old term for the joint between the coping and the deck is "Mastic Joint" Now a day's Deck-O-Seal has replaced the term or they are interchangeable...
So is it import at all? The simple answer YES!! The expansion joint is the rubbery substance that seals the coping to the deck. Its purpose is to allow independent movement of the pool and the deck, prevents water from getting behind the pool shell and eroding the dirt that holds the shell of the pool and supports the deck and it prevents water from getting behind or under the pools coping stones, causing cold mortar joints and freezing that can cause loose stones and loose tiles etc…
The Deck-O-Seal removal and installation is very labor intensive and runs about 6.00 per LF to remove and replace (includes labor and material). The expense comes from having to remove the old seal then back fill the crevasse with backer rod and sand then filling the remaining void with the mastic joint seal. It's allowed to cure with a finish top coating of sand. Your expansion joint/deco seal is a very important aspect for the overall protection of your swimming pool and decking. The expansion joint/deco seal plays an important role in allowing movement of the pools structure. So when movement is occurring (albeit deck or pool) during temperature change in the summer or when we have no rain or a lot of rain (dehydration/re-hydration) , the rubbery joint allows the pool to move independent of the deck rather than pressing into the decking which would cause cracking of the pool or the decking surface.
When the expansion joint/deco seal starts to fail or has separated from the pool coping or deck, it could allow water to run off into the joint causing water to build up as i said above. I have heard that a lack of mastic can also cause soil erosion over time that will allow the decking to crack along with water to settle near the re-bar in the shell structure of the pool. This may cause rust spots on the inside of the pool. In my opinion, rust spots occur from a bad re-bar placement i.e. being too close to the plaster surface, however anything is possible. Having a good expansion joint/deco seal will help to prevent those things from happening which over time will save you money.
When installing expansion joint/deco seal, you always want to go through the proper steps to ensure both the coping and deck surfaces are prepped 100% to guarantee the material adheres to the surface and last as long as possible. This means removing all of the old product. If you don’t you are most likely going to have premature failure of the new product. When doing the installation there is a specific way to achieve the best outcome possible. Cleaning the surfaces, installing a backer foam, sanding the area to fill the voids, then pouring the expansion joint/deco seal material and finally sanding the surface lightly to give it the natural look. And yes anyone CAN do it but it IS recommended that you get it professionally
installed. Believe me folks, some things are better left to ones who have the proper "know how"... because if this is done wrong or rushed it WILL LOOK TERRIBLE and your pool should be a show piece!
Here is some technical stuff if your interested:
DECK-O-SEAL is used for caulking and sealing joints subject to concrete movement to provide a firm, flexible, weather-tight seal. It is ideal for sealing joints on swimming pool decks. It is applicable for both interior and exterior use.
FEATURES/BENEFITS
I look forward to working with you and helping you enjoy your new pool!
Take Care and as always call or email with any questions,~Jason Thompson
Ocean Blue Pool Service - 469-358-1895
[email protected]
An old term for the joint between the coping and the deck is "Mastic Joint" Now a day's Deck-O-Seal has replaced the term or they are interchangeable...
So is it import at all? The simple answer YES!! The expansion joint is the rubbery substance that seals the coping to the deck. Its purpose is to allow independent movement of the pool and the deck, prevents water from getting behind the pool shell and eroding the dirt that holds the shell of the pool and supports the deck and it prevents water from getting behind or under the pools coping stones, causing cold mortar joints and freezing that can cause loose stones and loose tiles etc…
The Deck-O-Seal removal and installation is very labor intensive and runs about 6.00 per LF to remove and replace (includes labor and material). The expense comes from having to remove the old seal then back fill the crevasse with backer rod and sand then filling the remaining void with the mastic joint seal. It's allowed to cure with a finish top coating of sand. Your expansion joint/deco seal is a very important aspect for the overall protection of your swimming pool and decking. The expansion joint/deco seal plays an important role in allowing movement of the pools structure. So when movement is occurring (albeit deck or pool) during temperature change in the summer or when we have no rain or a lot of rain (dehydration/re-hydration) , the rubbery joint allows the pool to move independent of the deck rather than pressing into the decking which would cause cracking of the pool or the decking surface.
When the expansion joint/deco seal starts to fail or has separated from the pool coping or deck, it could allow water to run off into the joint causing water to build up as i said above. I have heard that a lack of mastic can also cause soil erosion over time that will allow the decking to crack along with water to settle near the re-bar in the shell structure of the pool. This may cause rust spots on the inside of the pool. In my opinion, rust spots occur from a bad re-bar placement i.e. being too close to the plaster surface, however anything is possible. Having a good expansion joint/deco seal will help to prevent those things from happening which over time will save you money.
When installing expansion joint/deco seal, you always want to go through the proper steps to ensure both the coping and deck surfaces are prepped 100% to guarantee the material adheres to the surface and last as long as possible. This means removing all of the old product. If you don’t you are most likely going to have premature failure of the new product. When doing the installation there is a specific way to achieve the best outcome possible. Cleaning the surfaces, installing a backer foam, sanding the area to fill the voids, then pouring the expansion joint/deco seal material and finally sanding the surface lightly to give it the natural look. And yes anyone CAN do it but it IS recommended that you get it professionally
installed. Believe me folks, some things are better left to ones who have the proper "know how"... because if this is done wrong or rushed it WILL LOOK TERRIBLE and your pool should be a show piece!
Here is some technical stuff if your interested:
DECK-O-SEAL is used for caulking and sealing joints subject to concrete movement to provide a firm, flexible, weather-tight seal. It is ideal for sealing joints on swimming pool decks. It is applicable for both interior and exterior use.
FEATURES/BENEFITS
- Highly resilient with excellent recovery characteristics
- Provides permanent and uniform watertight seal.
- Prevents uncontrolled cracking by allowing expansion and contraction during temperature changes.
- Stays flexible … won’t become brittle or crack due to ultraviolet exposure.
- Resists abrasion, weathering and moisture … elevated temperatures will not cause discoloration.
- Not affected by today’s pool chemicals.
- Retains joint soundness in service once it’s cured and can be stretched or compressed up to 25%.
I look forward to working with you and helping you enjoy your new pool!
Take Care and as always call or email with any questions,~Jason Thompson
Ocean Blue Pool Service - 469-358-1895
[email protected]
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